In the photographic processing to obtain color images by processing imagewise-exposed light-sensitive materials, there are generally provided, after color developing, desilverization of the metal silver formed and subsequent processes of washing and stabilizing or stabilizing which functions as washing concurrently.
These light-sensitive materials are processed in an automatic processor installed in individual processing laboratories. And as a part of customer service, processing laboratories are required to process and return light-sensitive materials to customers within the same day on which these are brought in for development. This tendency is growing recently, and there has come to be demanded return of light-sensitive materials within hours after being brought in. Under the circumstances, further improvements in the rapid processing technology are increasingly required.
To meet such requirements, Eastman Kodak Company, for example, recently proposed Process RA-4, a rapid processing for color paper which processes a light-sensitive material in 3 minutes at 35.degree. C. (comprising 3 processes of 45-second color developing, 45-second bleach-fixing and 90-second stabilizing).
Meanwhile, conventional techniques for rapid processing can be classified into three categories:
1) techniques to improve light-sensitive materials, PA1 2) techniques based on physical means in processing, and PA1 3) techniques to improve the composition of processing solutions used in processing.
In the above category 1), there have been proposed (1) improvements in silver halide composition, for example, a technique for preparing silver halide fine grains described in Japanese Pat. O.P.I. Pub. No. 77223/1976 and a technique to prepare low silver bromide content silver halide described in Japanese Pat. O.P.I. Pub. No. 18142/1983 and Japanese Pat. Exam. Pub. No. 18939/1981; (2) use of additives, for example, a technique to add in light-sensitive materials a 1-aryl-3-pyrazolidone having a specific structure as described in Japanese Pat. O.P.I. Pub. No. 64339/1981 and a technique to add in light-sensitive materials 1-aryl pyrazolidones described in Japanese Pat. O.P.I. Pub. Nos. 144547/1982, 50534/1983, 50535/1983 and 50536/1983; (3) techniques to employ rapid reaction couplers, for example, a technique to use rapid reaction yellow couplers described in Japanese Pat. Exam. Pub. No. 10783/1976 and Japanese Pat. O.P.I. Pub. Nos. 123342/1975, 102636/1976; and (4) techniques to form thin photographic structural layers, for example, a technique to form thin photographic structural layers described in Japanese Pat. O.P.I. Pub. No. 65040/1987.
The above category 2) includes techniques for stirring processing solutions, for example, a stirring technique for processing solutions described in Japanese Pat. O.P.I. Pub. No. 180369/1987.
With respect to the category 3), there are known (1) techniques to use developing accelerators; (2) techniques to use high concentration color developing agents; and (3) techniques to reduce a halogen ion concentration, particularly a bromine ion concentration in developer.
Among these rapid processing techniques, one which can provide an excellent rapid processability is a technique to use a light-sensitive material comprised of silver halide grains having high silver chloride content, which falls under the above category 1), embodiments of this technique can be seen, for example, Japanese Pat. O.P.I. Pub. Nos. 95345/1983, 19140/1985 and 95736/1983.
However, the rapid processing of a light-sensitive material containing silver halide grains having high silver chloride content has a drawback of causing unevenness in magenta in a colored portion, not a color stain occurring in an unexposed portion, when a light-sensitive material is processed in a solution having a bleaching capability subsequently to color developing.
Formation of magenta stain in an unexposed portion is observed at times even in light-sensitive materials containing silver bromide as the main component, when these are bleach-fixed immediately after color developing. And as a measure to solve such a problem, there is known to add a compound described below in a bleach or bleach-fixer containing EDTA Fe as the principal component of the bleaching agent.
For example, a technique to use L-ascorbic acid and 2-hydroxy-4-phenyltetronimide is disclosed in British Pat. No. 1,131,096, a technique to use morpholine in British Pat. No. 1,131,335, a technique to use para-aminophenol in British Pat. No. 1,133,500, a technique to employ polyalkylene polyamine in Japanese Pat. O.P.I. Pub. No. 136031/1975, and a technique to add sulfites to a bleaching solution containing EDTA.Fe as a principal component of the bleaching agent.
These techniques seem to be effective on light-sensitive materials containing silver bromide, but ineffective in preventing uneven magenta dye formation in a colored portion of a light-sensitive material in which silver chloride is used.
As a method to prevent such uneven magenta dye formation in a light-sensitive material whose main silver halide composition is silver chloride, Japanese Pat. O.P.I. Pub. No. 196662/1987 discloses a technique to remove benzyl alcohol from a color developer when a two-equivalent magenta coupler specified in the specification is used. But this method has no effect in preventing the uneven magenta dye formation in a colored portion.
The uneven magenta dye formation is attributed to a poor development stopping property of a bleach-fixer for high silver chloride content light-sensitive materials. Therefore, this problem has been prevented by keeping the pH of a bleach-fixer less than 6.5 and adding ammonium bromide thereto.
In this case, however, the low pH of less than 6.5 brings a problem of impairing the preservability of a bleach-fixer. For example, a bleach-fixer having a pH of less than 6.3 is placed on the market as a low replenishing type, but its use is limited to large-scale processing laboratories for its insufficient preservability. On the other hand, in case of a small-scale processing or low replenishment processing, precipitation of sulfur or sulfides in bleach-fixer is liable to occur. And once it occurs, light-sensitive materials in the solution are stained with precipitated sulfur or sulfides, the bleach-fixer's capability is lowered, and troubles such as poor desilverization and poor color formation are caused. In case of a heavy precipitation of sulfur or sulfides, processing becomes unable to continue without renewing the processing solution, and tanks and racks need to be cleaned. In addition, tar is formed in the bleach-fixer.
Further, addition of bromides to a bleach-fixer of low pH increases corrosiveness of the solution, causing rust on the surface of tanks or racks which contact with the solution. Though such rusting can be avoided by the use of titanium or SUS316L containing less carbon as the material of tanks and racks, it raises the equipment cost as compared with SUS316 which is used commonly.
Moreover, the opening area of a bleach-fixing tank has a large effect on processability as well as properties of a processing solution. An opening area smaller than a specific value hinders the air oxidation of a bleaching agent, causing processing failure. And an opening area larger than a specific value leads to an excessive decomposition of a preservative by air oxidation, and thereby preservability of a processing solution is deteriorated and corrosion of tanks and racks is accelerated.